Nanoparticles have emerged as a significant area of interest because of their distinct physicochemical properties and wide-ranging applications. Plant-derived nanoparticles offer advantages in terms of safety, environmental impact, sustainability, and potential applications compared to conventional methods. This chapter includes synthesis methods, different plant sources, and plant-based products, such as extracts that can stabilize and eliminate agents during the synthesis process. The chapter focuses on the methods and factors affecting the production of nanoparticles, such as reaction circumstances, plant species, and particle properties. Furthermore, applications for plant-derived nanoparticles in antibacterial, antiviral, antidiabetic, and other methods are also explored. This book chapter provides a better understanding of the innovative field of plant-based nanoparticle synthesis by providing an in-depth overview of current developments and challenges.